{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://lc-json.org/1.1-rc.1/publication-fields.schema.json",
  "title": "LC-JSON Shared Publication Field Group",
  "description": "The publication-metadata field group shared by the distributable artifact types (course, glossary, subjectCollection, curriculumPack) via allOf composition. Fields are plain optional top-level properties on each document root — there is no nested publication envelope. questionSet is excluded by role: it is a lightweight referencable content resource, not a distribution-governed one.",
  "type": "object",
  "properties": {
    "license": {
      "type": "string",
      "description": "License under which this document is distributed. 'unspecified' is appropriate only for private drafts; documents intended for distribution SHOULD carry a concrete license. SPDX identifiers (e.g. 'CC-BY-4.0') are recommended for recognizable licenses; 'mixed' or 'seeComponents' signal that embedded or referenced resources carry their own terms (typical for packs and courses embedding third-party material).",
      "default": "unspecified"
    },
    "canonicalUrl": {
      "type": [
        "string",
        "null"
      ],
      "format": "uri",
      "description": "URL where the authoritative copy of this document is published, when one exists. Null or absent means no canonical location is asserted.",
      "default": null
    },
    "derivedFrom": {
      "type": "array",
      "description": "Provenance chain: the document(s) this one was revised or remixed from. Each entry names a source document by its portable identity. A tool creating a new document by modifying an existing one SHOULD record the source here.",
      "items": {
        "type": "object",
        "properties": {
          "globalId": {
            "type": "string",
            "description": "The source document's globalId.",
            "minLength": 1
          },
          "version": {
            "type": [
              "string",
              "null"
            ],
            "description": "The source document's version at the time of derivation, when known.",
            "default": null
          }
        },
        "required": [
          "globalId"
        ]
      },
      "default": []
    }
  }
}